Title

Waterjet based demining using acoustics with maximum-likelihood and distance-based detection techniques

Author

Bhargav Mantha

Keywords and Phrases

Demining

Abstract

"The use of water jets is potentially a cost effective and efficient way to detect buried landmines. An object buried under the soil is squirted with a high pressure jet of water. The acoustic signal generated by the impact is picked up by a microphone and processed to determine the type of object.

A study of acoustics related to the waterjet was performed. Results of attempts to use silencers to muffle the sound of the jet are presented. The use of high density low porosity foam in the silencer reduced noise levels by 50%, but resulted in an incoherent waterjet stream. Attempts were made to model the object based on its resonant modes. The filtering characteristics of the borehole and its behavior as an open-ended pipe were also investigated. No firm conclusions were available from this study.

The Maximum Likelihood technique was used to detect and discriminate between objects. The power spectrum was used to characterize the signal. Different groupings based on object type were tested. Detection rates up to 93% were observed when objects were categorized as ‘harmless’ and ’harmful’. Receiver-Operating Characteristic curves were used to evaluate discrimination capability when the water jet hit an object or only soil. A probability of detection of 90% with a false alarm rate of 24% was observed.

Three distance measures, the Euclidean, Manhattan and Generalized distance, were tested to show their ability to detect when the waterjet hit an object. ROC curves were plotted for each measure. All the distance measures performed almost equally well, with an average P_f of 30% for average P_d of 90%"--Abstract, page iii.

Advisor(s)

Beetner, Daryl G.

Committee Member(s)

Agarwal, Sanjeev, 1971-
Stanley, R. Joe

Department(s)

Electrical and Computer Engineering

Degree Name

M.S. in Electrical Engineering

Publisher

University of Missouri--Rolla

Publication Date

Summer 2003

Pagination

viii, 56 pages

Note about bibliography

Includes bibliographical references (pages 52-55).

Rights

© 2003 Bhargav Shastry Mantha, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Subject Headings

Water jets
Land mines -- Detection
Mines (Military explosives) -- Detection

Thesis Number

T 8289

Print OCLC #

54790558

Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

Recommended Citation

Mantha, Bhargav, "Waterjet based demining using acoustics with maximum-likelihood and distance-based detection techniques" (2003). Masters Theses. 2358.
https://scholarsmine.mst.edu/masters_theses/2358